Microfluidic-enabled magnetic labelling of nanovesicles for bioanalytical applications

Area of Science:

• Nanomaterials Science
• Microfluidics
• Analytical Chemistry

Background:

• Multifunctional nanomaterials significantly enhance analytical assays by improving sensitivity, selectivity, sample preparation, and signal detection.
• Magnetic properties in nanoparticles and nanovesicles are crucial for overcoming diffusion limitations and improving separation efficiency in assays.

Purpose of the Study:

• To develop a microfluidic method for reliably labeling functional nanovesicles, preventing crosslinking and conglomerate formation common in bulk reactions.
• To covalently bind biotinylated fluorescent liposomes to magnetic beads within microfluidic channels using an optimized coupling strategy.

Main Methods:

• Activation of carboxy groups on biotinylated fluorescent liposomes.
• Covalent binding of activated liposomes to amino group-presenting magnetic beads immobilized via a magnetic field in microfluidic channels.
• Optimization of microfluidic design and coupling strategy for different magnetic bead sizes (1 μm beads and 30 nm magnetic nanoparticles).

Main Results:

• Achieved a 62% coupling efficiency using 1 μm magnetic beads.
• Observed a reduced yield of 13% with 30 nm magnetic nanoparticles, attributed to magnetic nanoparticle crowding.
• Demonstrated superior performance of the tri-functional liposomes in a biological binding assay under magnetic field influence.

Conclusions:

• The proposed microfluidic functionalization strategy enables efficient and controlled labeling of nanovesicles and nanoparticles.
• This method is suitable for massively parallelized production and scalable application to various micro- and nanosized vesicles and particles.
• The magnetic field-assisted functionalization enhances the performance of nanomaterials in biological binding assays.